Method for treating foodstuffs



Oct. 20, 1942. w. DE BACK v METHOD FOR TREATING FOODSTUFFS Filed May 14, 1940 l NVENTOR www A 1% ATTORN 0a. 20, 1942, WQ DE B K. 2,299,080

METHOD FOR TREATING FOOD'STUFFS Fil ed May 14'. 1940 r 2 Sheets-Sheet '2 lNV ENT I ATTORNEY Patented Get. 20, 1942 2,299,080 mnrnon non rnm'rmo roonsrurrs William de Back, Niagara Falls, N. Y., assignor a @hisholm-Ryder Gompany, Incorporated, Niagara Falls, N. Y., a corporation of New York Application May 14, 1940, Serial No. 335,115

Claims.

of the vegetables in a liquid for a predetermined time in order to blanch the same or otherwise alter the color, appearance, structure or taste of the vegetables. The process is herein described more particularly as a blanching process in which the foodstuffs to be blanched, together with enough covering liquid, are passed in small individual batches in succession through a heated chamber following which the batches are drained and can be rinsed. However, it will be understood that the process can be carried out for other purposes, as for the treatment of peas in a potassium chloride solution to improve the quality and appearance of the peas or in a coloring process where the foodstuffs are held immersed in a coloring solution.

This application is a continuation in part of my application Serial No. 289,858, filed August 12, 1939, for Apparatus for treating foodstufis.

One of the objects of the invention is to provide such a process in which the treating liquid can be used only once and then discarded and in which the minimum amount of such treating liquid is employed so as to avoid waste of the I liquid.

Another object of the invention is to provide 1 such a process which can be carried out with simple apparatus and in which the materials to be treated, together with the necessary amount of treating liquid, are conveyed in separate successive batches.

Another object of the invention is to provide such a process in which the batches of materials to be treated and the treating liquid can be heated.

Another object of the invention is to provide such a process in which the treating liquid is continuously agitated and in which the materials are handled in such manner as to avoid injury to tender materials.

Another object of the invention is to provide such a process in which the materials to be treated can be washed to remove any debris and in which the wash liquid, after being screened, can. be subsequently used in the treating process.

Another object is to provide such a process in which the additions of fresh treating liquid can be under simple float valve control, thereby to insure constant operating conditions.

Another object of the invention is to provide such a process which is continuously in operation and can be used to handle large amounts of materials in a short period of time and which will produce a product of constant quality and can be readily controlled.

In the accompanying drawings: 7

Fig. 1 is a vertical longitudinal section of a rotary blancher suitable for use in carrying out my invention.

Figs. 2, 3 and 4 are vertical transverse sections, taken on the correspondingly numbered lines of Fi 1.

As an example of one use to which my invention can be applied, the accompanying drawings illustrate a blancher which includes a tank III which is shown as being semicylindrical in cross section and is suitably supported on legs H. At one end this tank is provided with an end head i2 and at its opposite end is provided with an extension having an inclined lower wall l3 and side walls M. The tank It carries four drum supporting rollers l5, 'one pair of these rollers being located at the front end of the tank and rotatably supporting a metal tire or ring l6 of a cylindrical horizontal imperforate drum l1 and the other pair of rollers l5 supporting a similar ring or tire l8 secured to the rear end of the drum IT. The drum l1 provides the blanching or treating chamber and is internally provided with a helical strip l9, this strip forming a screw for positively conducting materials and the treating liquid from the inlet end of the drum H to the outlet end in separate, independent batches. The outer edge of the helix I9 is preferably welded to the interior of the imperforate drum l1 and is of suflicient depth to permit the drum to convey both the treating liquid and the materials to be treated positively and in separate batches to the discharge end of the drum. The inner diameter of this strip is preferably large enough to permit a person to enter the drum l1 forthe purpose of cleaning the screw conveyer or repairing the same.

When used for blanching, water is employed as the treating liquid but, as previously pointed out, special solutions, particularly salt solutions, such as magnesium chloride, can be employed.

' At its discharge end the drum I7 is provided with a circular end head 20 which has a coaxial.

shown).

I the drum a circular concentric casting 22 which forms a discharge neck and is also formed to provide a sprocket 23, this sprocket being driven by a drive chain 24 from any suitable source of power (not It will therefore be seen that as the sprocket 23 is turned by the drive chain 24 the drum I1 is rotated and the materials fed to the leading end of the screw is will be separated into individual batches, these batches being moved in succession lengthwise of the drum II.

The materials so supplied to the inlet end'of V I1 comprise the vegetables to be blanched or otherwise treated and suflicient preheated water or other treating liquid to cover the vegetable, any desired proportion of which can be fresh liquid. To supply the vegetables a bar screen 25 is removably mounted in any suitable manner on the end head l2 of the tank In, this bar screen comprising an inclined frame 28 which is formed to hook over the end head l2 and supported by the tank I at its lower end to discharge into the open end of the drum H. The frame 28 carries a plurality of bars 21 which insure the delivery of the materials to be blanched tothe lead end of the screw l9 and also permits blanching water to flow from the tank Ill to the lead end of this screw so as to provide the amount of water necessary to cover the batches of materials separated by the screw l9 and conducted lengthwise of the imperforate drum H.

The water admitted to the tank I0 is under control of a float valve 30, the float 3| of which ispreferably arranged in a tank 32 which is connected with the main tank Ill by a duct 33. The float 3| is therefore responsive to the level of the water in the tank l0 and operates to control the admission of fresh water from a pipe 34 to a water inlet 35 in the extension l3, ll of the tank In. The float valve 30 can be adjusted to maintain any desired level in the tank. i0 and hence in the drum I1, the drum l1 being submerged in this water to an extent suiiicient to provide water in the batches picked up by the'screw l5.

Heat for blanching the materials conveyed in separate batches by the screw I! may be supplied by a steam pipe 40 arranged longitudinally under the center of the drum I1 and having a plurality of openings 4| in its upper part through which steam is discharged, this steam preheating the blanching water flowing through the tank l0 toward its left hand end as viewed in Fig. 1 and also rising to heat the drum l1 and hence the batches of materials being conveyed there-' through. The addition of fresh water through the inlet 35 is made in the extension l3, H of the tank I 0 and it will therefore be seen that this water must be preheated by the steam pipe 40 before being mixed with the material to be blanched. Further, it will be seen that the rotation of the drum, the movement of the water through the tank l0 toward the inlet end of this drum and the agitation provided by the steam issuing through the ports 4|, serves to maintain a uniform water temperature at the lead end of the screw IS.

The blanching drum l1 and tank I0 is hooded toprevent the escape of steam except through the proper vents. For this purpose a semicircular hood 42 is provided, the lower edges of which rest on the upper edges of the semicircular tank ID, as best shown in Fig. 2, and this hood being provided with an end head 43 across the inlet end of the drum I1 and an end head 44 at the other end of the drum II. This hood is providedwith a vent 45 through which the vapor escapes.

The trailing end 50 of the screw i9 terminates short of the circular end head 20 of the drum and three buckets Si, 52 and 53 are provided for lifting the blanched materials and water from the space between the screw and the end head 20 and discharging them through the neck 22 into a rotary screen 54. For this purpose each of the discharge buckets comprises a chute having an inner plate 58 and side walls 51 and 58, the chutes inclining toward one another toward the discharge opening in the casting 22 and the wall 58 of each chute being extended radially outward, as indicated at 59, to engage the end head 20 and the adjacent inner face of the drum ll. With the chutes 5| and 52 radial plates 60 are provided each of which is secured to the inner edges of the corresponding plates 56, 51 and 58 and is also welded to the adjacent inner surface of the drum ll so as to form a bucket which lifts the material from the space inside of the drum l1 beyond the trailing helix of the screw and discharges the material into the chute formed by the plates 58. 51 and 58 when the bucket assumes the elevated position of the bucket 53, Fig. 1, the inclination of this chute in this position discharging this material into the rotary screen 54, as shown. The bucket 53 is arranged at the trailing end 50 of the screw IQ and hence with this bucket the plate 6|! is eliminated, the trailing end of the screw being substituted for these plates.

It will be noted that the plates of each of the buckets 5| and 52 are in the same transverse vertical plane as the trailing edge 50 of the screw i9. Since the flnal helix of the screw I9 is spaced a greater distance from the plate 60 of the bucket 5| than the plate 80 of the bucket 52, it will be seen that the bucket 5| picks up only a part of the material betweenthe final helix of the screw l9 and the end head 20 of the drum. As the next bucket 52 rotates to the bottom of the drum i9 it will pick up an additional amount of the ma terial trapped between the final helix of the drum l9 and the end head 20. Since the trailing end 50 of the screw forms a part of the bucket 53, it will be seen that the remainder of such trapped material will be picked up and discharged by this bucket 53. Therefore each batch of material conveyed beyond theflnal helix of the screw I9 is picked up and discharged into the screen 54 in three separate batches, this avoiding injury to tender materials during a transfer to the rotary screen and also providing a moderate uniform feeding of material to the rotary screen.

The screen rotates with the drum l1 and for this purpose is secured to the end of the circular casting 22 by a ring 65, or in any other suitable manner. The screen 54 carries at its opposite discharge end a sheet metal head 66 of frusto conical form to provide an opening 61 of reduced diameter through which the blanched materials are discharged from the apparatus.

The rotary screen 54 carries an internal helical flight 10 which conveys the blanched materials axially of the screen and discharges these materials through the opening 81. The water discharged by the buckets 52 and 53 passes through the rotary screen 54 into a separate discharge basin H arranged in and extending transversely the full width of the extension l2, [4 of the tank Hi. This discharge basin has a waste outlet 12 connected with an adjustable overflow pipe 13, this adjustable overflow pipe being capable of being swung to any angle so as to discharge all or any desired proportion of the spent water caught by the basin H. One wall of the basin is formed to provide an adjustable overflow dam having for this purpose a plate 14 which can be adjusted vertically to any desired position. It will be seen that upon adjusting the overflow pipe 13 and the overflow dam 14 any desired proportion of the spent water caught by the basin 1! can be returned to mix with the fresh water from the inlet 35 for reuse in the blanching process. Whether any part of the treating liquid is reused depends upon the nature of the process and the nature of the liquid which may be employed. In quality blanching and in otherprocesses for treating vegetables, the treating liquid is usually so affected by the process that it is undesirable to reuse any large proportion of the treating liquid.

If desired the blanched drained materials can be washed before being discharged through the opening 61in the discharge end of the rotary screen 55. For this purpose a wash liquid pipe 15 is provided which extends into the screen 54 through this opening 51 and is drilled to provide downward jets '86 which wash the materials conveyed through the screen 54 after passing beyond the basin 1!. To catch any debris washed from the blanched materials by the sprays 16 a removable screen 11 is arranged under the rotary screen below the sprays 1B. The wash liquid draining from the blanched materials is thereby caught by the removable screen 11 which entrains any debris from this liquid, the liquid thereafter mixing with the liquid used for blanching. It will be noted that by this means the blanched materials are cooled before being discharged from the screen 54 and at the same time the wash liquid is heated by the blanched material before being mixed with the liquid used during the blanching operation. It will also be noted that the screen '11 can readily be removed and cleaned and that the frusto conical form of the head 5?! serves to insure the return of wash liquid to the screen 11.

The level of the water or liquid in the tank it can also be adjusted to a maximum amount by an adjustable overflow pipe 18 which is connected to the duct 33 and capable of being swung to any position so as to discharge a greater or less quantity of the water from the tank it and maintain a desired level.

The carrying out of the process forming th subject of my invention in blanching vegetables with the above described apparatus is as follows:

While in operation the imperforate drum I1 is being rotated on its supporting rolls by the chain drive 24, this also turning the rotary screen 54 and its helical flight 10. The materials to be blanched are fed in a continuous stream to the bar screen which conducts these materials to the lead end of the screw I9. Wash water may be supplied through the pipe 15 and the desired level of the blanching water within,

the tank it is maintained by the float valve supplying fresh water through the inlet 35. Steam is supplied to the steam pipe 40, this steam emerging through the perforations 4| in this pipe, and the dam 14 and adjustable overflow pipe 13 are set to waste any desired proportion of the spent blanching water passing into the basin ll, that proportion of the water not wasted through the overflow pipe 13 passing over the overflow dam 14 and being recirculated.

The water from the fresh water'inlet 35, wash flows through the tank 10 toward the inlet end of the rotary drum l1. In so flowing this water passes the steam pipe 40 and is preheated preparatory to its being used for blanching. The water so flowing through the tank Ill is also agitated by the steam issuing from the perforations 4! and by the rotary movement of the drum l1 so that it is of uniform temperature before being admitted to the inlet end of the drum l1. As the lower part of the screw i1 is immersed in this water, each rotation of the lead end of the screw l9 picks up a batch of the material to be blanched as well as enough preheated water to cover this material. The successive batches picked up by the lead end of the screw are then positively advanced by the screw to the discharge end of the imperforate drum 11, these batches being subjected to the heat of the steam issuing from the steam pipe 40' and being blanched. By providing a screw conveyer, as shown, the material to be blanched is positively controlled, this being effected by adjusting the speed of rotation of the drum l1, and hence it will be seen that a definite blanching time is provided. It will further be seen 7 that by blanching in separate'batches the danger of contamination is reduced and is entirely eliminated if all of the spent blanching water received the basin 1| is wasted. As each batch passes beyond the final helix of the screw IS a part of this batch is picked up by the bucket 5i and when this bucket reaches the top of the drum the material so picked up is discharged through its inclined chute 56, 51, 58 into the rotary screen 54. The bucket 52 then similarly picks up another part of the batch delivered by the screw 19 to the discharge end of the drum l1 and the remainder of this batch is similarly picked up and discharged into the screen 54 by the third bucket 53.

The water from the material so discharged onto the rotary screen by the buckets 5|, 52 and 53 passes through the rotary screen 54 into the basin 1! from which all of this spent water can be wasted through the adjustable overflow pipe 13.

jected to the washing action of the sprays 16,

these sprays servin to cool the blanched materials and at the same time the spray water being heated by the blanched materials. This spray water, together with any debris washed from the blanched materials, flows onto the removable screen 11 which catches any debris, the wash water joining the fresh and recirculated water supplied to the tank I i] and being used for blanching purposes. It will also be noted that the form of the head 66 insures the draining of the blanched material and the return of substantially all the wash water to the removable screen 11 which can be easily removed for the purpose of cleaning the same.

sprays 16 and any water overflowing the dam 14 With the blancher as shown access can readily be had to all parts by removal of the hood 42 which serves to prevent the escape of vapor except through the vent 45. It will also be seen that the screw 19 is self-cleaning but that if desired a person can enter the drum 1! for the purpose of cleaning or repairing the screw and the interior of the drum. It will also be noted that the level of the blanching water in the tank can be adjusted so that it will just cover the material to be blanched, thus rendering the blancher economical in the use of water and steam. This also makes it possible in many instances to use the blanching water only once, as a minimum amount of such water isemployed. Where a part of, the water is recirculated it will be noticed that this water is positively circulated because of the pumping action of the screw I9 in the imperforate drum II.

From the foregoing it will be seen that the process forming the subject of the invention is extremely economical in the use of both the treating liquid and steam; in which a positive control of the material being processed is obtained; in which improved color and. flavor of the product can be obtained; in which provision is made for draining and rinsing the treated materials and in which the materials need only be provided with sufllcient treating liquid to insure complete immersion, the liquid not being used as an agent in conducting the materials through the apparatus.

I claim as my invention:

1. The method of treating foodstuffs which comprises positively conveying the foodstuffs to be treated from one end of a chamber to the other, moving an enclosed body of treating liquid underneath and along the full length of the exterior of said chamber in heat exchan ing relation thereto and countercurrent to and out of contact with the flow of foodstuffs to be treated, adding predetermined amounts of said liquid to the foodstuffs to be treated before entering said chamber and applying heat through saidbody of liquid while so moving underneath the exterior of said chamber to treat the foodstuffs bein conveyed through said chamber.

2. The method of treating foodstuffs which comprises positively conveying the foodstuffs to be treated in relatively small, individual batches horizontally, in continuous succession from one end of an enclosed chamber to the other and in direct contact with the exterior wall thereof, moving a body of treating liquid underneath and along the full length of the exterior of said chamber in heat. exchanging relation thereto and countercurrent to and out of contact with the flow of foodstuffs to be treated, adding a predetermined amount of said liquid to each of said batches offoodstuffs to be treated before entering said chamber, confining said amount of treating liquid with each of said batches of foodstufis during the entire course of said batches through said chamber, and applying heat through said body of liquid while so moving underneath the exterior of said chamber to treat the foodstuffs being conveyed through said chamber.

3. The method of treating foodstuffs which comprises positively conveying the foodstufl's to be treated from one end of an enclosed chamber to the other and in direct contact with the exterior wall thereof, moving a body of treating liquid underneath and along the exterior of said chamber in heat exchanging relation thereto and countercurrent to the flow of foodstufl's to be treated, adding predetermined amounts of said liquid to the foodstuffs to be treated before entering said chamber, applying heat through said body or liquid while so moving underneath the exterior of said'chamber to treat the foodstuffs being conveyed through said chamber, immediately separating the liquid from the treated foodstuffs upon their discharge from said chamber, returning one portion of said separated liquid to said body of liquid and adding fresh liquid to said body of liquid in an amount equal to the other portion of said separated liquid and before apply heat to said body of liquid.

4. The method of treating foodstuffs which comprises positively conveying the foodstuffs to be treated in individual batches from one end of an enclosed chamber to the other and in direct contact with the exterior wall thereof, moving a body of treating liquid underneath and along the exterior of said chamber in heat exchanging relation thereto and countercurrent to the flow of foodstuffs to be treated, adding a predetermined amount of said liquid to each of said batches of foodstuffs to be treated before entering said chamber, introducing steam into said body of liquid while so moving underneath the exterior of said chamber to treat the foodstuffs being conveyed through said chamber, im-

' mediately separating said liquid from the treated i body of treating liquid underneath and along the exterior of said chamber in heat exchanging relation thereto and countercurrent to the flow of foodstuffs to be treated, adding a predetermined amount of said liquid to each of said batches of foodstuffs to be treated before entering said chamber, confining said amount of treating liquid with each of said batches of food- -stuffs, introducing steam into said body of liquid while so moving underneath the exterior of said chamber to treat the foodstuffs being conveyed through said chamber, immediately separating said liquid from the treated foodstuffs upon their discharge from said chamber, returning one portion of said separated liquid to said body of liquid and adding fresh liquid in an amount equal to the other portion of said separated liquid and before applying heat to said body of liquid.

WEIIAM n1: BACK. 

